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add a missed loop deletion case.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126103 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2011-02-21 02:13:39 +00:00
parent 408b534e43
commit 19310fc199
1 changed files with 14 additions and 0 deletions
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14
lib/Target/README.txt
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@ -254,6 +254,20 @@ unsigned long reverse(unsigned v) {
//===---------------------------------------------------------------------===// //===---------------------------------------------------------------------===//
[LOOP DELETION]
We don't delete this output free loop, because trip count analysis doesn't
realize that it is finite (if it were infinite, it would be undefined). Not
having this blocks Loop Idiom from matching strlen and friends.
void foo(char *C) {
int x = 0;
while (*C)
++x,++C;
}
//===---------------------------------------------------------------------===//
[LOOP RECOGNITION] [LOOP RECOGNITION]
These idioms should be recognized as popcount (see PR1488): These idioms should be recognized as popcount (see PR1488):